1. Field of the Invention
This invention relates generally to missiles and more particularly to tube-launched operator-guided missiles
2. Description of Related Art
Tube-launched operator-guided missiles were first developed over a decade ago and have proven very effective against such targets as tanks, personnel carriers, bunkers, and the like.
A large part of these missiles' effectiveness and appeal is their simple operational concept. The operator of the missile "guides" the missile to the target. Communication with the missile is through a wire or fiber optic link. Using a telescope pointing mechanism, the operator controls the missile to avoid field obstructions such as trees or hills. Since the operator controls the line of flight, a great operational burden is removed from the missile itself, and the brains or complexity, required in other types of missiles, is reduced. This significantly reduces the cost of the missile.
As far as applicant is aware, these missiles currently receive the operator generated signals in analog form. The analog form is adequate for the communication of signals since the missile's electronic control unit utilizes changes in voltage in the communication link (a pair of thin steel lines) for providing the desired flight control.
Several problems attend the use of analog circuits. Where the incoming signal is analog, the electronics unit is also analog. However, being analog in nature, the electronics unit has been relative bulky and complex.
Another major difficulty with analog circuits, is that modification of the circuit's objective or operation is very difficult, requiring almost a total re-engineering of the circuit. Once a missile has been tested, even a slight control function change disrupts the layout of the entire analog circuit. This restraint inhibits the engineers from "fine tuning" the electronics unit.
The electronics unit implements the commands of the operator by adjusting the pitch and yaw control surfaces which guide the missile.
Another feature of these missiles is modularity. The various components making up these missiles (e.g. the warhead, the electronics unit, the flight motor, the launch motor, etc.) are unique and separate modules. This use of modules permits the missile to not only be maintained easily, but also allows it to be component upgraded without undue re-engineering of the entire system.
In this regard, the traditional design for tube-launched operator-guided missiles has placed the electronics unit directly behind the warhead in a forward position on the missile. Because of the bulk of the analog electronic unit, space is not available for the electronics unit aft.
Also, because of an overall length restriction, the bulky electronics unit limited the volume available for the warhead. For some targets, the limited size of the warhead is a disadvantage.
Still another disadvantage is with the electronics unit in a forward position, the balance of the missile is adversely affected. Compensating ballast is required in the aft section. This ballast only added to the weight considerations which required compensation in other areas (sometimes further reducing the warhead size).
It is clear from the forgoing that the present analog electronics unit creates many engineering problems which hinder the ready upgrade of tube-launched operator-guided missiles.